<template>
	<div>
		<router-link tag="div" to="/" class="header-abs" v-show="showAbs">
			<div class="iconfont header-abs-back">&#xe64e;</div>
		</router-link>
		<div class="header-fixed" v-show="!showAbs" v-bind:style="opacityStyle">
			<router-link to="/">
				<div class="iconfont header-fixed-back">&#xe6bc;</div>
			</router-link>
			景点详情
		</div>
	</div>
</template>

<script>

export default {
	name: 'DetailHeader',
	data () {
		return {
			showAbs: true,
			opacityStyle: {
				opacity: 0
			},
		}
	},
	methods: {
		handleScroll () {
			const top=document.body.scrollTop || document.documentElement.scrollTop//兼容写法
			if (top > 60 ) {
				let opacity = top / 140
				opacity = opacity > 1 ? 1 : opacity
				this.opacityStyle = { opacity }
				this.showAbs = false
			} else {
				this.showAbs =true
			}
		}
	},
	activated () {
		window.addEventListener('scroll', this.handleScroll)
	},
	deactivated () {
		window.removeEventListener('scroll', this.handleScroll)
	}
}
</script>

<style lang='stylus' scoped>
  @import '~__STYLES__/varibles.styl'
  .header-abs
    position: absolute
    left: .2rem
    top: .2rem
    width: .8rem
    height: .8rem
    line-height: .8rem
    border-radius: .4rem
    text-align: center
    background: rgba(0, 0, 0, .8)
    .header-abs-back
      color: #fff
      font-size: .4rem
  .header-fixed
    z-index: 2
    position: fixed
    top: 0
    left: 0
    right: 0
    height: $headerHeight
    line-height: $headerHeight
    text-align: center
    color: #fff
    background: $bgColor
    font-size: .32rem
    .header-fixed-back
      position: absolute
      top: 0
      left: 0
      width: .64rem
      text-align: center
      font-size: .4rem
      color: #fff
</style>